Optimal decision-making method for equipment maintenance to enhance the resilience of power digital twin system under extreme disaster

Digital twins and the physical assets of electric power systems face the potential risk of data loss and monitoring failures owing to catastrophic events,causing surveillance and energy loss.This study aims to refine maintenance strategies for the monitoring of an electric power digital twin system post disasters.Initially,the research delineates the physical electric power system along with its digital counterpart and post-disaster restoration processes.Subsequently,it delves into communication and data processing mechanisms,specifically focusing on central data processing(CDP),communication routers(CRs),and phasor measurement units(PMUs),to re-establish an equipment recovery model based on these data transmission methodologies.Furthermore,it introduces a mathematical optimization model designed to enhance the digital twin system’s post-disaster monitoring efficacy by employing the branch-and-bound method for its resolution.The efficacy of the proposed model was corroborated by analyzing an IEEE-14 system.The findings suggest that the proposed branch-and-bound algorithm significantly augments the observational capabilities of a power system with limited resources,thereby bolstering its stability and emergency response mechanisms.

Paths to Enhance Teacher Digital Literacy Under Educational Digital Transformation in China

In the context of the digital transformation of education in the new era,digital literacy for teachers is a new requirement for professional development.Teacher digital literacy encompasses four main aspects:attitudinal literacy,knowledge and skills literacy,instructional application literacy,and innovation and development literacy.Currently,there are several issues with teacher digital literacy,such as a lack of digital responsibility,insufficient digital knowledge and skills,weak digital application skills,and low digital innovation capability.Enhancing teachers’digital literacy is a complex and critical task.Based on the current state of teachers’digital literacy,this paper proposes the following approaches:(1)adherence to digital norms;(2)development of a robust training mechanism;(3)improvement of the evaluation system;(4)strengthening of digital innovation.

Follow-up of endovascular aortic aneurysm repair:Preliminary validation of digital tomosynthesis and contrast enhanced ultrasound in detection of medium- to long-term complications

AIM: To validate the feasibility of digital tomosynthesis of the abdomen(DTA) combined with contrast enhanced ultrasound(CEUS) in assessing complications after endovascular aortic aneurysm repair(EVAR) by using computed tomography angiography(CTA) as the gold standard.METHODS: For this prospective study we enrolled 163 patients(123 men; mean age, 65.7 years) referred for CTA for EVAR follow-up. CTA, DTA and CEUS were performed at 1 and 12 mo in all patients, with a maximum time interval of 2 d.RESULTS: Among 163 patients 33 presented complications at CTA. DTA and CTA correlated for the presence of complications in 32/33(96.96%) patients and for the absence of complications in 127/130(97.69%) patients; the sensitivity, specificity, positive predictive value(PPV), negative predictive value(NPV) and accuracy of DTA were 97%, 98%, 91%, 99%, and 98%, respectively. CEUS and CTA correlated for the presence of complications in 19/33(57.57%) patients and for the absence of complications in 129/130(99.23%) patients; the sensitivity, specificity, PPV, NPV and accuracy of CEUS were 58%, 99%, 95%, 90%, and 91%, respectively. Sensitivity, specificity and accuracy of combining DTA and CEUS together in detecting EVAR complications were 77%, 98% and 95%, respectively.CONCLUSION: Combining DTA and CEUS in EVAR follow-up has the potential to limit the use of CTA only in doubtful cases.

Modeling the special intersections for enhanced digital map

A new lane-level road modeling method based on cardinal spline is proposed for the special intersections which are covered by vegetation or artificial landscape in their central regions.First,cardinal spline curves are used to fit the virtual lanes inside special intersections,and an initial road model is established using a series of control points and tension parameters.Then,the progressive optimization algorithm is proposed to determine the final road model based on the initial model.The algorithm determines reasonable control points and optimal tension parameters according to the degree of road curvature changes,so as to achieve a balance between the efficiency and reliability of the road model.Finally,the proposed intersection model is verified and evaluated through experiments.The results show that this method can effectively describe the lane-level topological relationship and geometric details of this kind of special intersection where the central area is covered by vegetation or artificial landscape,and can achieve a good balance between the efficiency and reliability of the road model.

Modified method for extraction of watershed boundary with digital elevation modeling

Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver wa-tershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was extracted by digital elevation modeling (DEM) data in ArcInfo8.1. Remote sensing image of the corresponding region was applied to help modify its copy according to Enhanced Thematic Mapper (ETM) image抯 profuse geomorphological structure information. Both the DEM-dependent boundary and modified copy were overlapped with county map and drainage network map to visually check the effects of result. Overlap of county map suggested a nice extraction of the boundary line since the two layers matched precisely, which indicated the DEM-dependent boundary by program was effective and precise. Further upload of drainage network showed discrepancies between the boundary and the drainage network. Altogether, there were three sections of the extraction result that needed to correct. Compared with this extraction boundary, the modified boundary had a better match to the drainage network as well as to the county map. Comprehensive analysis demonstrated that the program extraction has generally fine precision in position and excels the digitized result by hand. The errors of the DEM-dependant extraction are due to the fact that it is difficult for program to recognize sections of complex landform especially altered by human activities, but these errors are discernable and adjustable because the spatial resolution of ETM image is less than that of DEM. This study result proved that application of remote sensing information could help obtain better result when DEM method is used in extraction of watershed boundary.

“Deep-time Digital Basin” Based on Big Data and Artificial Intelligence

1 Introduction Information technology has been playing an ever-increasing role in geoscience.Sphisicated database platforms are essential for geological data storage,analysis and exchange of Big Data(Feblowitz,2013;Zhang et al.,2016;Teng et al.,2016;Tian and Li,2018).The United States has built an information-sharing platform for state-owned scientific data as a national strategy.

The digital mapping produced with satellite image of the Zhongshan Station area in Antarctica

Ice and snow domint the land features in Antarctica. The great brightness and poorcontrast of ice and snow and streaking noise in satellite image make the procedure of image processing difficult. On the other hand however, the contrast between bare rock land/sea water and ice/snow is so high that the details of image will be overcompressed.In the light of characteristics of satellite image in Antarctica, a filtering to remove streaking noise has adn discussed. Based on automatic identify classification to enhance the details of objects and the method and theory of digital rectification of satellite image with ground control points measured from field survey are also presented.

Effect of ionizing radiation on dual 8-bit analog-to-digital converters (AD9058) with various dose rates and bias conditions

The radiation effects on several properties （reference voltage, digital output logic voltage, and supply current） of dual 8-bit analog-to-digital （A/D） converters （AD9058） under various biased conditions are investigated in this paper. Gamma ray and 10-MeV proton irradiation are selected for a detailed evaluation and comparison. Based on the measurement results induced by the gamma ray with various dose rates, the devices exhibit enhanced low dose rate sensitivity （ELDRS） under zero and working bias conditions. Meanwhile, it is obvious that the ELDRS is more severe under the working bias condition than under the zero bias condition. The degradation of AD9058 does not display obvious ELDRS during 10-MeV proton irradiation with the selected flux.

Research on Influence of Electromagnetic Interference on X-Ray Digital Detection

X-ray digital imaging technology has found wide application owing to its advantages of real-time, visualization and rapid imaging. In substations the substantial electromagnetic interference has some influence on the live detection by the X-ray digital imaging technology, hindering the promotion of the technology in the detection of electric equipment. Based on a large number of field tests, the author carded out a series of researches on electromagnetic interference protection measures, image de-noising, and image enhancement algorithms.

数字乡村建设对壮大农村集体经济的作用效应

壮大农村集体经济发展是带动农业农村发展,实现中国式农业农村现代化的重要抓手和动力引擎。本文基于2020年和2021年“中国土地经济调查”的数据,利用熵值法测算出数字乡村建设水平的综合指数,在此基础上采用固定效应模型实证考察数字乡村建设对壮大农村集体经济发展的影响效应及作用机制。研究发现:数字乡村建设能显著地促进农村集体经济的壮大发展,本结果在经过内生性和稳健性检验后依然稳健;机制分析显示,数字乡村建设通过提升人力资本水平、促进资源要素集聚、推动产业结构升级壮大农村集体经济的发展;进一步异质性分析发现,数字乡村建设尚未对村级集体经济发展实现包容性增长,数字乡村建设对低等收入组的村级集体经济发展并未发挥正向带动作用。此外,相比低产业化经营发展水平的村庄,数字乡村建设对高产业化经营发展水平的村级集体经济壮大发展促进作用更显著。上述结论对数字乡村建设可作为壮大农村集体经济发展的动力引擎提供了实证依据和决策参考。

微光数字观瞄镜的强杂光抑制技术研究

针对观瞄镜强杂光干扰问题,提出一套完整的强杂光抑制技术方案。首先,对物镜内表面采用绒布消光;然后,在软件图像处理上结合使用相邻图像累加积分、直方图统计和宽动态灰度增强等算法完成强杂光抑制;在天空照度为1×10^(-3)lx以下的野外暗夜环境下,加入强杂光干扰后进行实验测试。实验结果表明,该技术方案能有效完成强杂光抑制和图像细节增强,提升图像质量。软件算法在FPGA(Field Programmable Gate Array)平台上运行,2 ms内完成图像处理工作,满足实时性要求。

美国佛罗里达大学图书馆提升馆员数字学术服务能力的实践与启示

[目的/意义]图书馆员的数字学术服务能力是开展高质量数字学术服务的重要保障。深入剖析国外高校图书馆提升馆员数字学术服务能力的实践项目,可以为国内高校图书馆提升馆员数字学术服务能力提供参考和借鉴。[方法/过程]文章以美国佛罗里达大学数字人文图书馆小组实施的“发展中的图书馆员”项目为研究对象,基于文献调研和网络调研的方法,从实施背景、实施特点和成效评估3个方面调研了该项目的实施经验。[结果/结论]“发展中的图书馆员”项目利用有限的人力、经费和空间资源有效提高了图书馆员开展数字学术服务的技能和信心、激发了更多图书馆员参与数字学术服务的意愿和兴趣。建议国内高校图书馆在借鉴经验的基础上,从4个方面着力提升图书馆员的数字学术服务能力:自上而下倡导数字学术服务理念、由浅入深设计馆员能力培训方案、由表及里开展项目成效评估工作、由内而外建立数字学术实践社区。

基于GaAs E/D PHEMT工艺的Ku波段双通道幅相控制多功能芯片

基于GaAs增强/耗尽型赝配高电子迁移率晶体管(E/D PHEMT)工艺设计了一款14~18 GHz的双通道多功能芯片。芯片集成了单刀双掷(SPDT)开关、6 bit数控移相器、4 bit数控衰减器和增益补偿放大器。采用正压控制开关以减小控制位数;优化移相、衰减和放大等电路拓扑结构,以获得良好的幅相特性;采用紧凑布局、双通道对称的版图设计,以实现小尺寸和高性能。测试结果表明,+5 V电压下,接收通道增益大于3 dB,1 dB压缩点输出功率大于8 dBm;发射通道增益大于1 dB,1 dB压缩点输出功率大于2 dBm;64态移相均方根误差小于2.5°,16态衰减均方根误差小于0.3 dB,芯片尺寸为3.90 mm×2.25 mm。该多功能芯片可实现对射频信号幅度和相位的高精度控制,可广泛应用于微波收发模块。

数字经济赋能河南乡村产业融合发展的路径探索

“农业+”是乡村产业融合发展模式,数字经济在推动乡村产业融合发展方面发挥着不可忽视的作用。河南是农业大省,故探究数字经济赋能河南乡村产业融合发展的路径很有意义。在“农业+旅游”中,要通过智能化手段,提升乡村旅游价值,提升旅游产品品质和服务质量。在“农业+文化”中,要挖掘乡村文化资源,运用数字技术,创新历史文化的表现形式,打造特色文化产业,构建产业链,并塑造品牌,以提升经济效益,实现产业可持续发展。在“农业+教育”中,要通过数字技术,提供优质教育资源,开展农业科普,并创新教育形式,增加互动体验,以提升服务和管理效率,改善教育效果。在“农业+体育”中,要利用数字媒体,融合文化元素,打造乡村体育IP,提高赛事知名度,以赛促产,完善乡村体育设施,构建完整的产业链。总之,要强化数字经济赋能,激发乡村产业的内生动力,推动河南乡村经济高质量发展。

数智融合视阈下的全民数字素养提升系统动力学研究

为应对数字化转型换挡提速,数智融合视阈下国民数字化操作形态的转变为全民数字素养提升打开了新视角。以数智融合为切入点,对数字素养相关理论进行梳理,搭建契合数字中国建设背景的数智融合视阈下的全民数字素养框架,并在此基础上构建系统动力学模型,利用Vensim PLE软件进行仿真模拟。仿真结果表明,该模型能较好地反映数智融合视阈下的全民数字素养的现实情况,揭示数智融合视阈下的全民数字素养的内部结构与演化规律。最后根据仿真结果提出数智融合视阈下的全民数字素养提升路径。

工业4.0背景下高职院校教师数字能力内涵演进、框架分析及提升策略

人类社会进入工业4.0时期,教育领域需要重新思考未来社会所需人才的能力,特别是在数字化、智能化层面的能力。高职院校作为培养高素质技术技能人才的教育机构,数字化转型势在必行,而教师具备合格的数字化知识和能力以及积极的态度是促进职业院校数字化转型的关键。从职业教育发展历程出发,对高职院校教师数字能力内涵进行分析,借鉴国内外8个代表性文献所提出的教师数字能力框架,构建了包括公民数字能力、数字教学能力、专业数字能力3个方面12个能力因素的高职院校教师数字能力框架,提出从“文化引领+靶向认证”“数字赋能+正非结合”“组织架构+平台支撑”三个方面构建高职院校教师数字能力提升策略。

数字金融对企业技术创新的影响——基于金融活动路径视角分析

数字金融作为科技与金融的深度融合,对企业创新和经济高质量发展有着重要影响。基于2011—2020年中国沪深A股上市公司数据,以企业进行的金融活动为探索机制,分析数字金融对技术创新的影响。研究表明:数字金融可以通过缓解企业股权融资约束、提升企业投资水平、减少营运资本产生的挤出效应驱动技术创新。进一步分析表明,金融发展水平发展越好的地区,数字金融对技术创新的正向影响越显著;在数字金融情境下,技术创新带动企业管理创新,促进企业价值提升,对经济高质量发展存在正向促进作用。

基于数字化赋能的城市儿童亲自然创新发展

当前城市儿童与自然之间的情感联系缺失已影响儿童身心健康的成长,随着科技的不断进步与数字化技术的空间赋能,儿童接触和体验自然的方式不断发生变化。文章以城市存量绿色空间为载体,结合当前数字化技术发展,探索城市儿童亲自然体验的发展模式,分析总结面向儿童成长的自然教育发展阶段,并基于生态场景、数字场景与知识场景,提出构建数字化赋能的自然教育发展框架,并以徐汇田林社区公园、上海创智农园等数字化应用为例,详细阐述知识场景增强的数字化科普学习模式和自然体验增强的线上+线下情境化模式,探讨数字化赋能提升当前绿色空间的服务效能、体验维度、情境内容与知识学习的路径,以促进当代城市儿童亲自然力的发展,实现儿童亲自然行为、情感和认知能力的增强。

数字经济时代下体育用品制造业供应链韧性提升的路径研究

数字经济时代下的体育用品制造业供应链韧性提升是培育新质生产力、实现体育产业现代化的重要内容,也是在当今国际国内复杂环境中保持竞争力的关键举措。研究采用文献资料、逻辑分析等方法,探讨数字经济时代下体育用品制造业供应链韧性提升的基本内涵、内在机理与制约因素,并提出推进路径。研究认为,数字经济时代下体育用品制造业供应链韧性提升的内在机理主要体现在4个层面:结构优化层面,加速供应链数字化升级;技术创新层面,推进供应链自主可控;效率提升层面,优化供应链资源配置;安全保障层面,改进供应链治理方式。但在此过程中存在数字技术应用程度有限、技术创新动力与能力不足、数字鸿沟与信息孤岛明显、数据安全与监管体系尚不健全等诸多制约因素。为此,提出强化数字基础与配套设施建设,提升体育用品制造业供应链结构调整能力;推动“产学研”深度融合,提升体育用品制造业供应链自主创新能力;拓宽数据集成与流通渠道,提升体育用品制造业供应链主体交互协作能力;健全数据安全与监管体系,提升体育用品制造业供应链安全管理能力。

基于数字衍射的单幅眼底图像增强

彩色眼底图像是分析与监控眼底疾病的重要工具。由于照明不均匀的问题,眼底图像视觉质量不足,图像对比度有待提高。为此,基于数字衍射提出了一种兼顾颜色保真与亮度增强的单幅眼底图像光强校正算法。将彩色RGB眼底图像转换到LCH色彩空间进行基于L通道的光强校正,以解决眼底图像亮度的平衡问题。对C通道进行相同操作使得处理后的彩色眼底图像颜色保真性较好。在Messidor眼底图像数据集的1200组眼底图像上进行分析,并与Gamma校正、Retinex等眼底图像光强校正方法进行对比。本算法不仅具有更好的图像增强效果,改善了彩色眼底图像的颜色失真及对比度低的问题,还可进一步结合自适应直方图均衡化(CLAHE)以提升图像对比度。实验结果表明,在图像多尺度对比度和图像噪声评价指标方面优于传统算法3%~4%。经算法增强后眼底图像亮度分布更加均匀、对比度提升,为后期眼底图像病理位点的识别、血管与病灶分割和分类提供了一种性能更好的预处理方法。